Typically, an electronic device (e.g. notebook/desktop computers, cell phones, etc.) has a power controller or voltage regulator that controls one or more power chains, or powertrains, to provide a stable and efficient power supply for some of the device's electronic components (e.g. central processing units and graphic processing units, among other types of integrated circuits). The design of the power controller generally depends on the type of power chain application into which the controller is to be incorporated. Common power chain applications typically have one of two primary design types: a discrete power MOSFET design or an integrated Driver-MOSFET (DrMOS) design.
As the name implies, a circuit 100 using a typical discrete power MOSFET design generally includes one or more power chains 102, 104 and 106, each having a high-side discrete power MOSFET 108 and a low-side discrete power MOSFET 110 external to a power controller 112, as shown in a simplified example in FIG. 1. When operated by the power controller 112, the discrete power MOSFETs 108 and 110 function together (with an output inductor 114 and an output capacitor 116, among other components not shown for simplicity) to produce the desired electrical power at Vout1, Vout2-VoutN. In such an application, therefore, the power controller 112 generally has to produce one or more sets of coordinated pairs of driver signals (high-side MOSFET driver signals DH1, DH2-DHN and low-side MOSFET driver signals DL1, DL2-DLN, among other signals not shown for simplicity) for properly controlling the function of the high-side and low-side discrete power MOSFETs 108 and 110. The high-side and low-side MOSFET driver signals DH1, DH2-DHN and DL1, DL2-DLN are generally based on a pulse-width modulated (PWM) signal 118 (produced by a PWM generator 120 within the power controller 112), but are sufficiently powerful to drive the discrete power MOSFETs 108 and 110 at an appropriate rate.
On the other hand, a circuit 122 using a typical DrMOS design generally includes one or more power chains 124, 126 and 128, each having a DrMOS integrated circuit (IC) DrMOS1, DrMOS2 and DrMOSN connected to a power controller 130, as shown in a simplified example in FIG. 2. Some DrMOS ICs (e.g. DrMOS1, DrMOS2 and DrMOSN) are defined by the standard DrMOS specification, available from Intel Corporation. Other integrated driver-MOSFET designs, which do not comply with the Intel specification, are also available. The term “DrMOS” is, thus, used herein to cover cases where a MOSFET driver 132 is combined with high-side and low-side power MOSFETs 134 and 136 in a switching power stage external to an IC of the power controller 130. Each DrMOS IC DrMOS1, DrMOS2 and DrMOSN, thus, drives an output inductor 138 and an output capacitor 140, among other components (not shown), to produce the desired electrical power at Vout1, Vout2-VoutN. Instead of producing driver signal pairs for MOSFETs, therefore, the power controller 130 simply has to produce a PWM signal PWM1, PWM2 and PWMN for a “PWM Input” of each DrMOS IC DrMOS1, DrMOS2 and DrMOSN. Consequently, the power controller 130 in a DrMOS-based application can be simpler, smaller and cheaper than the power controller 112 (FIG. 1) in a discrete power MOSFET application. Additionally, integration of the MOSFET driver 132 with the high-side and low-side power MOSFETs 134 and 136 in a single IC (or IC package) can result in cost and size benefits for a DrMOS-based application compared to a discrete power MOSFET application.
There is a basic incompatibility between the power controllers used with discrete power MOSFETs and the power controllers used with DrMOS ICs. In particular, the MOSFET driver signals DH1, DH2-DHN and DL1, DL2-DLN (FIG. 1) produced by the discrete MOSFET power controller 112 cannot be used to drive the PWM Inputs of the DrMOS ICs. Additionally, the PWM signals PWM1, PWM2 and PWMN (FIG. 2) produced by the DrMOS power controller 130 cannot be used to drive the discrete power MOSFETs 108 and 110, even if the PWM signals PWM1, PWM2 and PWMN are split into inverted and non-inverted signals. This incompatibility is primarily due to anti cross conduction, timing and edge characteristics (among other distinctive attributes) of the MOSFET driver signals and the PWM signals that are essential for proper functioning in their respective intended application, but which render the MOSFET driver signals unsuitable for use in a DrMOS-based application and the PWM signals unsuitable for use in a discrete MOSFET application.
In spite of the general advantages of DrMOS-based applications over discrete power MOSFET applications, there has been a relatively slow adoption of the DrMOS standard by the designers and manufacturers of the electronic devices in which these power chain design types are used. As a result, the designers and manufacturers of the power controllers for use in these two design types have to produce at least two different power controllers (or families of power controllers), since the same power controller cannot be used in both types of applications, even though either design type could conceivably be used in the same electronic device. In other words, the designers and manufacturers of the power controllers must maintain availability of at least two SKUs (stock keeping units) for power controllers that are basically redundant in spite of being of incompatible designs. As is usually the case, however, larger numbers of SKUs generally lead to lower efficiencies in resource utilization and inventory management and, thus, higher costs for each SKU.
It is with respect to these and other background considerations that the present invention has evolved.